It can also be safely consumed by people with lactose intolerance. Although its ingredients vary extensively depending upon the manufacturer, the basic ingredients- milk and bacteria culture remain the same.
Low fat yogurt is made from low fat milk while a fat free one is made from skimmed milk. The usual plain, full fat one is made from whole milk. Milk can also be combined with other dairy products, such as cream, in order to adjust the fat content. Sometimes, dry milk may also be used to obtain the desired consistency.
Milk can often be substituted by soy milk in order to prepare soy yogurt. In this case water and ground soy are mixed together to get soy milk, and lactic acid may be added externally. Usually it is naturally present in all dairy products.
Mostly, cultures of Lactobacillus bulgaricus and Streptococcus thermophilus are used together for manufacturing yogurt. Although these cultures can work on their own, the acid production during their symbiosis is far more than when individual species are used.
Additionally, cultures of Lactobacillus acidophilus, Lactobacillus casei, and Bifido-bacteria are also used as probiotic bacteria. These bacteria are good for gastrointestinal problems and relieve symptoms, such as bloating, gas, stomach pain etc. They also reduce the occurrence of fungal infections and maintain the general health of colon.
Apart from the two basic ingredients mentioned earlier, commercially available yogurt also contains some additives and artificial sweeteners. The other flavoring ingredients are given here.
Organic yogurt makers prefer to use evaporated cane juice as a sweetening agent, instead of artificial sweeteners. Evaporated cane juice is also a part of most soy yogurts.
If the fruit is packaged at the bottom of the yogurt pack, then this type is termed as 'set-style yogurt'. On the other hand, if the fruit is blended in it, then the yogurt is referred as 'Swiss style yogurt'. Artificial coloring agents may be added to emphasize a particular fruit flavor.
Commercially, yogurt is manufactured by separating fat from the milk. Other dairy products may be added to achieve desired consistency and fat content. The mixture is then agitated to thoroughly mix the various ingredients and then pasteurized.
Stabilizers are added to the mixture after which the mixture is homogenized. Strains of Lactobacillus bulgaricus and Streptococcus thermophilus are added in equal proportions. An optimum growth temperature is maintained to initiate the fermentation process.
The coagulated product is then collected and various flavoring and coloring agents are added. Fruits may be added at this stage and then the yogurt is packaged. The processed yogurt is then stored at a temperature of about 5°C.
While making it at home, you will only require the basic ingredients i.e milk and culture. Homemade yogurt is an healthy option as it is freshly prepared and free from any artificial ingredients.